Method of purifying fats.



No. 722,832. I PATENTED MAR. 17, 1903.

v 0. FRESENIUS.

v METHOD OF PURIFYING FATS.

APPLICATION FILED SEPT. 22, 1902.

N0 MODEL.

Tia: uonms PETERS 60.. PHOTD-LITHU., wAsumu'rmi, 0. c4

UNITED STATES PATENT OFFICE.

CARL FRESENIUS, OF OFFENBACI-I-ON-THE-MAIN, GERMANY.

METHOD OF PUR IFYING FATS.

SPECIFICATION forming part of Letters Patent No. 722,832, dated March17, 1903.

Application filed September 22, 1902.

To all whmn it may concern:

Be it known that I, CARL FRESENIUS, a citizen of the German Empire,residing at Offenbach-on-the-Main, in the Grand Duchy of Hesse, Germany,have invented certain new and useful Improvements in or Relating to thePurification of Fats and Oils, Particularly of Cocoanut-Oil; and I dohereby declare the following to bea full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

In the purification of fat oils and fats for eating purposes it isimportant in the first place to remove the free fatty acids. To this endsuitable solutions of alkalies and alkaline earths are used. In order toprecipitate the enormous soap emulsion thus produced, particularly ifalkaline earths, such as lime, &c., be used, it has hitherto beennecessary to heat the masses for a long time up to 100 centigrade.Moreover, for the removal of the free fatty acids of the oils and fatslarger quantities of alkalies have, as a rule, been used than aretheoretically required for the chemical reaction. These quantities ofalka lies attack organic substances more or less, but particularly at ahigh temperature. This action is diminished or the substances havingodor or flavor produced thereby are rendered innocuous by means of purefresh carbon, &c. Fats and oils which have not been subjected topurification in the presence of preventive means against the injuriousinfluence of the product of decomposition, either during or shortlyafter their production, can never comply with the high conditionsrequisite in articles of food, even if they are repeatedly purifiedafterward. This fact is often the drawback in the production of oils andfats for eating purposes.

In the drawing the figure is a vertical section through the apparatusused in carrying out this invention.

I have discovered that the soap emulsion produced upon the addition ofalkalies can rapidly be precipitated and a more complete binding of thefree fatty acids can be obtained if the mixtures are subjected for ashort time to pressure in a closed vessel above the pressure of theatmosphere until Serial No. 124,448- (No specimens.)

the mass has attained a heat corresponding to the pressure. In order toprevent the injurious influence of air, heat, pressure, a preventivemeansas, for instance, pure fresh carbon or similarly-actin gsubstancesis first added. The action of the carbon, '&c., as a means forpreventing the injurious influence of air, heat, and pressure (thelatter being merely inclosed heat in-this case) may be explained asfollows: The small quantities of pure carbon or coal-d ust and the likewhich serve as protecting means during this temporary treatment surroundthe oil and fat and should therefore be added simultaneously with thealkalies before the heating, and consequently before the action of hotair, in order to protect the oils and fats against damage by the'oxygenof the air and the organic products of decomposition caused or favoredby the alkalies, so as to prevent, as far as possible, the fats becomingrancidthat is, acquiringa bad taste and smell. In-

.fusorial earth or fullers earth may and under certain circumstancesmust be substituted for the carbon. In the necessary final treatmentwith compressed steam of the oils and fats first freed from fatty acidsminimum traces of alkalies remaining from the first treatment must beretained in or added to fats and oils rich in stearin, and particularlyto such animal fats and oils, in order to render the decomposition oftraces of these fats harmless by saponification.

The usual final treatment of the oils and fats with larger quantities ofcarbon or other color-removing means and filtrations is not identicalwith the present method either as regards the manner of using the carbonor its action.

A vessel 1) for the fat or oil is provided and is arranged inside aclosed outer vessel a. The vessel to is provided with a manhole f, asafety-valve g, a pressure-gage h, a thermom eter 2', a water inlet pipe61, a Water gage 7n, and a Water-outlet pipe e, all of which parts areof any approved construction. A'steam heating-coil c is arranged in thelower part of the vessel a, and water is admitted to the said vesseluntil it reaches the water-line or level a: w. The inner vessel 1) isprovided with a series of gages Z for indicating the height of thevarious layers of its contents. It has also an inlet-pipe m and anoutlet-pipe n.

In carrying outthe invention one thousand pounds of oil are mixed witheleven pounds of charcoal or any other purifying agent which is theequivalent of charcoal. A neutralizing solution of lime is then added ina quantity suflicient to saponify the oil and the emulsion is wellstirred. The emulsion is admitted to the vessel 1) through the pipe m.Steam is admitted to the coil 0 at a pressure sufficient to raise thecontents of the vessel 2) to a temperature of about 300 Fahrenheit,thereby forming a pressure in the vessel 01 of about fifty-five poundsabove the pressure of the atmosphere. The emulsion is subjected CARLFRESENIUS.

Witnesses CARL SCHMITT, GUSTAV SINNHOLD.

